1. Field of the Invention
This invention relates to improvements in a method and an apparatus for syringing reaction beads produced as a result of reaction of sample and reagent with a syringing liquid in the examination of blood or the like, which is performed using reaction beads with coating of an antibody.
2. Description of the Prior Art
The syringing of reaction beads in the examination of blood or the like is usually performed using an apparatus as shown in FIG. 1. The apparatus has a titration plate 2 which supports a plurality of flasks 20 like test tubes, into which reaction beads 1 are charged together with samples and reagent for reaction and which are arranged in a matrix array. The plate 2 is held on top of a table 3 of a body a of a syringing apparatus A. A syringing liquid is poured into the flasks 20 from supply nozzles 41 which depend from a supply head 4 mounted in the body a above the table 3. The supply head 4 also has suction nozzles 40 extending parallel to the supply nozzles 41, thereby sucking out the poured syringing liquid by the nozzles 40.
For the syringing of reaction beads in the examination of blood or the like which is performed with this apparatus, the supply nozzles 41 and suction nozzles 40 are brought into a state with their free ends intruding into the flasks 20 as shown in FIG. 2, by raising the table 3 with a lifter 30 operated by a motor M or lowering the supply head 4 by operating a lifter (not shown). In the syringing operation, the syringing liquid is supplied from the supply nozzles 41 into the flasks 20 and is also sucked by the suction nozzles 40 therefrom. During this operation, the free open ends of the suction nozzles 40 are submerged in the syringing liquid which has been supplied continuously from the supply nozzles 41 and collected in the flasks 20. In this state, the suction nozzles 40 suction out the collected syringing liquid, whereby the reaction beads 1 and flasks 20 are syringed efficiently. When the syringing process is ended, the supply of syringing liquid is stopped, and the syringing liquid remaining in the flasks 20 is sucked out by the suction nozzles 40. At this time, the level of syringing liquid in each flask 20 is progressively reduced, and each free open end of the suction nozzles 40 eventually comes out of the liquid level so that it now withdraws air together with the syringing liquid. When this occurs, the suction pressure is no longer sufficient to withdraw all the syringing liquid remaining under the reaction bead 1 on the bottom of the flask 20. Consequently, a slight amount of syringing liquid remains on the bottom of the flask 20.
When the syringed reaction bead 1 is transferred from the flask 20 into a separate test vessel for the purpose of measurement of the status of the surface of the syringed reaction bead 1 with a colorimeter or like measuring instrument, the syringing liquid remaining on the bottom of the flask 20 after end of the syringing liquid suctioning operation is poured together with the reaction bead 1 into the test vessel. This causes an error of measurement of the changes of antibodies on the surface of the reaction bead 1. For this reason, it is desired to remove the syringing liquid completely from the flask. For the disposal of the remaining syringing liquid, however, drying means can not be used because an error is caused in the measurement of the reaction bead 1 if the surface thereof becomes dry.
Therefore, it has been proposed such means to have an end portion of the suction nozzle 40 depending from the supply head 4 to be capable of being flexed by a spring member and have a shape such that it reaches the bottom of the flask 20 under the reaction bead 1. This means, however, has a problem in maintenance in that an open end 40a of the suction nozzle 40 is deformed into a irregular shape when it is used many times.